FIG. 1 is a schematic diagram of network architecture of LTE system.
A Mobility Management Entity (MME) and an eNB are connected via an S1-MME interface; an eNB completes the access network function and communicates with user equipment (UE) through an air interface. For each UE attached to the network, there is an MME serving it, which is referred to as the serving MME of the UE. An S1-MME interface provides control panel service for UE, including mobility management and bearer management functions.
A Serving GW (S-GW) and an eNB are connected via an S1-U interface, and for each UE attached to the network, there is an S-GW serving it, which is referred to as the serving S-GW of the UE. An S1-U interface provides user plane service for UE, and a data packet of the user plane of UE is transmitted between an S-GW and an eNB via an S1-U GTP (GTP, GPRS Tunneling Protocol; GPRS, General Packet Radio Service) bearer.
In the prior art, connection management function requires participation of mobility entity MME of a core network. An MME of the core network is usually deployed at a location quite far from access network element(s). Therefore, once UE's connection status changes, the signaling process will affect the core network, not only causing signaling burdens on the backhaul between the radio access network and the core network, but also introducing additional transmission delay of the backhaul between the radio access network and the core network.
In summary, the current LTE network structure will cause signaling burdens on the backhaul between the radio access network and the core network, as well as lead to transmission delay of the backhaul.